Hearing devices provide sound for the wearer. Some examples of hearing devices are headsets, hearing aids, speakers, cochlear implants, bone conduction devices, and personal listening devices. Hearing aids provide amplification to compensate for hearing loss by transmitting amplified sounds to their ear canals. In various examples, a hearing aid is worn in and/or around a patient's ear.
Adaptive feedback cancellation is used in many modern hearing aids. Adaptive feedback cancellation algorithms perform poorly in the presence of strongly self-correlated input signals, such as pitched speech and music. The performance degradation results in lower added stable gain, and audible artifacts, referred to as entrainment. Signal processing systems that reduce entrainment by processing the output of the hearing aid can restore stable gain, but introduce additional audible sound quality artifacts. These artifacts may occur during voiced speech, but are most egregious for music signals, in which persistent tones aggravate the entraining behavior and magnify the sound quality artifacts.
There is a need in the art for improved feedback cancellation to mitigate unwanted adaptive feedback cancellation artifacts, such as those from entrainment, in hearing devices.